Chemoenzymatic synthesis of selenoneine and its analogs

Abstract

Disclosed is a method for forming selenoneine or analogs thereof. The method may include phosphorylating sodium selenide to a selenophosphate, using adenosine triphosphate (ATP) and at least a first protein, generating a selenosugar by converting the selenophosphate using at least a second protein in the presence of a common sugar donor, and forming selenoneine or an analog thereof by combining the selenosugar with N,N,N-trimethyl-L-histidine or analogs thereof using at least a third protein. The method may include combining SenA, SenB, and SenC in an aqueous buffer at neutral pH and ambient temperature, and allowing SenA, SenB, and SenC to form selenoneine or an analog thereof in the presence of ATP, a common sugar donor, and sodium selenide.

What is claimed: 
     
         1 . A method for forming selenoneine or analogs thereof, the method comprising:
 phosphorylating sodium selenide to a selenophosphate, using adenosine triphosphate (ATP) and at least a first protein;   generating a selenosugar by converting the selenophosphate using at least a second protein in the presence of a common sugar donor; and   forming selenoneine or analog thereof by combining the selenosugar with N,N,N-trimethyl-L-histidine or analog thereof using at least a third protein.   
     
     
         2 . The method according to  claim 1 , wherein the common sugar donor is UDP-glucose. 
     
     
         3 . The method according to  claim 1 , wherein the selenosugar is 1-seleno-N-acetyl-β-D-glucosamine. 
     
     
         4 . The method according to  claim 1 , wherein the first protein is coded by a selD homolog, the second protein is a glycosyltransferase, and the third protein is coded by an egtB homolog. 
     
     
         5 . The method according to  claim 1 , wherein the first protein is SenC, the second protein is SenB, and the third protein is SenA. 
     
     
         6 . The method according to  claim 1 , wherein forming selenoneine or an analog thereof by combining the selenosugar with N,N,N-trimethyl-L-histidine includes forming hercyncyl-SeGlcNAc selenoxide (GlcNAc-SEN=O), and allowing hercyncyl-SeGlcNAc selenoxide (GlcNAc-SEN=O) to spontaneously convert to selenoneine or be reduced to hercynyl-SeGlcNAc seleno-ether (GlcNAc-SEN). 
     
     
         7 . The method according to  claim 1 , further comprising purifying the selenoneine or analog thereof. 
     
     
         8 . The method according to  claim 1 , wherein the first protein, second protein, and/or third protein are fused to an affinity tag. 
     
     
         9 . A method for forming selenoneine or an analog thereof, the method comprising:
 combining SenA, SenB, and SenC in an aqueous buffer at neutral pH and ambient temperature; and   allowing SenA, SenB, and SenC to form selenoneine or an analog thereof in the presence of ATP, a common sugar donor, and sodium selenide.   
     
     
         10 . A kit comprising:
 one or more vectors, comprising:
 a first gene coding for at least SenC; 
 a second gene coding for at least SenB; 
 a third gene coding for at least SenA; 
   optionally adenosine triphosphate;   optionally a common sugar donor;   optionally sodium selenide; and/or   optionally hercynine or an analog thereof.